Assumptions
These are the default modeling assumptions behind the calculator. They are intentionally simple so the tool stays transparent and easy to audit.
Rental model
Starting property value
Rental wealth starts from the entered after-repair value (ARV), then compounds by the appreciation rate.
Collected rent
Gross rent is monthly rent times 12, reduced by vacancy percentage before management fees are applied.
Operating expenses
Management, maintenance, CapEx, property tax, insurance, and HOA are deducted from rent to calculate NOI.
Expense inflation
Property tax, insurance, and HOA are inflated at 2.5% annually in long-term rental projections.
Financing
Mortgage payment
Debt service uses principal and interest only. Taxes, insurance, HOA, repairs, and reserves stay in operating expenses.
ARM loans
The initial rate is used through the fixed period. The remaining balance is re-amortized at the adjusted rate afterward.
All-cash scenarios
All-cash rental and flip scenarios remove debt service and interest carry but require the full purchase price upfront.
Closing costs
Buy-side closing costs are modeled as a percentage of purchase price in all four scenarios.
Flip model
Sale value
Flip revenue uses the entered ARV as the resale price.
Holding costs
Holding costs include property tax, insurance, HOA, utilities, and, for financed flips, simple interest carry.
Selling costs
Selling costs and transfer tax are modeled as percentages of ARV.
Annualized return
Flip ROI is annualized by the entered hold period so short flips can be compared with long rentals.
Verdict
Benchmark
The best annualized return is compared against a 7% passive-investing benchmark.
Strong Buy
Best annualized return is at least 10%, beating the benchmark by 3+ points.
Makes Sense
Best annualized return is at least 7% but below 10%.
Pass
If the best scenario has no profit, the calculator marks the deal as a pass.
Defaults
New Jersey
Default property tax is 2.23%; default transfer tax is 1.0%.
New York
Default property tax is 1.54%; default transfer tax is 0.4%.
Local variation
State defaults are broad placeholders. Local rates, exemptions, mansion taxes, and municipal charges may differ.
Storage
Saved deals
Saved analyses are stored only in the browser's localStorage under
dealScan.savedDeals.v1.No syncing
Saved deals are local to the current device and browser. They are not uploaded or shared.
Input responsibility
The calculator does not verify rents, ARV, taxes, repair costs, insurance, loan terms, or comps.
Verify every assumption before making an investment decision.